Classical music affects how modern music is composed and performed.
Modern music covers a broad range of styles, genres and functions. Film music, popular music, concert music---all modern music inherits elements from the past. Here are some ways in which classical music affects the music we listen to today.
Musical Instruments
Modern music is often performed using the same types of instruments that were used during the classical era of Western music. Even today's electronically produced sounds tend to imitate and bare the namesakes of earlier classical musical instruments. Some examples include horns, new-age strings, harps, keyboards, and more---all possible with electronic synthesizers.
Musical Form
The form music has taken through the ages has not radically changed. We still have opera, even rock opera, jazz suites that are collections of short jazz-inspired pieces, symphonies, string quartets, and contemporary worship music, whose form is like its classical ancestors, but which has a distinctly modern style. One popular form of modern music, with roots in folk music as well as classical music, is the strophic song, with verses and a repeated chorus, used by many modern singer-songwriters.
Function and Presentation
Today some people listen to music on an iPod or MP3 player even more frequently than they attend live concerts. While past generations did not have our electronics, they used music for the same functions, and developed ways of presenting music, such as concerts and recitals. Although a concert in eighteenth century Vienna was certainly different from a modern rock concert, the idea is the same: performing artist or group on stage, and audience seated or standing out front.
Music Fusion
In modern music it is common to combine various kinds of popular and ethnic music with classical music to form fusion styles. The increased interest in world music has contributed to this trend. Many modern "classical" composers, also known as nationalists, have composed music that borrows ideas from classical music, national folk music, jazz, rock and roll, and more.